1. Field of the Invention
The present invention relates to a liquid crystal panel and to a liquid crystal display apparatus. In particular, the present invention relates to a liquid crystal panel suitable for a liquid crystal display apparatus and capable of providing a neutral display having no color shift in all azimuth angle directions, and to a liquid crystal display apparatus using the liquid crystal panel.
2. Description of the Related Art
FIG. 5A is a schematic cross-sectional view of a conventional typical liquid crystal display apparatus, and FIG. 5B is a schematic cross-sectional view of a liquid crystal cell used in the liquid crystal display apparatus. A liquid crystal display apparatus 900 includes a liquid crystal cell 910, retardation plates 920, 920′ placed on outer sides of the liquid crystal cell 910, and polarizing plates 930, 930′ placed on outer sides of the retardation plates 920, 920′. Typically, the polarizing plates 930, 930′ are placed so that absorption axes thereof are perpendicular to each other. The liquid crystal cell 910 includes a pair of substrates 911, 911′, and a liquid crystal layer 912 as a display medium placed between the substrates. One substrate 911 is provided with switching elements (typically, TFTs) controlling the electrooptical properties of liquid crystal, and scanning lines that supply a gate signal to the switching elements and signal lines that supply a source signal to the switching elements (not shown). The other substrate 911′ is provided with color layers 913R, 913G, 913B constituting a color filter, and a light-shielding layer (black matrix layer) 914. The interval (cell gap) between the substrates 911, 911′ is controlled with spacers (not shown).
The retardation plates are used for the purpose of optical compensation of a liquid crystal display apparatus. In order to obtain optimum optical compensation (for example, the improvement of viewing angle properties, the improvement of a color shift, and the improvement of a contrast), various attempts have been made with respect to the optimization of the optical properties of the retardation plates and/or the arrangement in the liquid crystal display apparatus. Conventionally, as shown in FIG. 5A, one retardation plate is placed between the liquid crystal cell 910 and the polarizing plate 930, and between the liquid crystal cell 910 and the polarizing plate 930′ (for example, see JP 11-95208 A).
Along with the recent increase in definition and function of a liquid crystal display apparatus, there is a further demand for the enhancement of uniformity and display quality of a screen. However, in a conventional liquid crystal display apparatus, it is difficult to express a neutral display having no color shift in all azimuth angle directions. Further, along with the miniaturization and the increase in portability of a liquid crystal display apparatus, a demand for the reduction in thickness is also increasing.